A couple of thoughts.
"The camera was set to Program mode with the ISO on automatic, allowing the camera to freely adjust anything it needs to get the correct exposure."
Should the camera be allowed to do that if you're demonstrating how various metering affects the photo? (not sure about this myself)

"That's the great thing about the AEL button - it allows you to control your exposure."
Maybe this could appear at the start, not the end.
Something like "The AEL button is really useful to help expose your photos well. This is what it can do ....... . However before we look at in depth we need to look at the other metering modes available in your camera so you can see the best way to use it."

And finally, you need to mention Canon as well as those other blokes.